code: def test_03_retrain_predictor(self):
      query = f"RETRAIN {self.test_model_1}"
      response = self.handler.native_query(query)
      self.assertTrue(response.type == RESPONSE_TYPE.OK)
  
imports: import os
  import time
  import unittest
  import tempfile
  from mindsdb.migrations import migrate
  from mindsdb.utilities.config import Config
  from mindsdb.integrations.utilities.test_utils import HandlerControllerMock, PG_HANDLER_NAME, PG_CONNECTION_DATA
  from mindsdb.interfaces.database.integrations import integration_controller
  from mindsdb.integrations.handlers.lightwood_handler.lightwood_handler.lightwood_handler import LightwoodHandler
  from mindsdb.interfaces.storage.fs import FsStore
  from mindsdb.interfaces.model.model_controller import ModelController
  from mindsdb.integrations.libs.response import RESPONSE_TYPE
  import mindsdb.interfaces.storage.db
label_desc: Use image node_id 5 for calling the LightwoodHandlerTest obj's underlying member method code with example usage: obj.test_03_retrain_predictor() without return types